The diagnosis of BPD in a CMHC is frequently challenging . Incorrectly diagnosing a patient as suffering from a unipolar mood disorder or from a[unreadable] [unreadable] disruptive behavior disorder leads to sub-optimal outcome and may worsen the course of BPD. Part of the difficulty[unreadable] [unreadable] is the current lack of consensus regarding the phenomenology of juvenile BPD. At present, there[unreadable] [unreadable] also is no certainty about the base rate at which BPD might present at a CMHC, nor is there an established set of[unreadable] [unreadable] instruments that could be used to screen a juvenile community sample for bipolar spectrum disorders. The need is great for such a screening protocol, given the long-term trajectory and[unreadable] [unreadable] serious consequences of untreated or mistreated BPD, and the potential value of early intervention and prophylaxis[unreadable] [unreadable] if cases could be identified in youths. Preliminary evidence from this research group suggests that several measures[unreadable] [unreadable] perform well at distinguishing BPD from unipolar depression, disruptive behavior disorders, and other disorders in[unreadable] [unreadable] children and adolescents. However, these findings were based on a sample presenting at a hospital outpatient clinic[unreadable] [unreadable] at an academic medical center specializing in the treatment of juvenile mood disorders and psychopharmacology[unreadable] [unreadable] research. Thus, several factors prevent the immediate application of existing findings to a community setting,[unreadable] [unreadable] including the lack of soundly-established base rates of BPD at community-based mental health centers, the[unreadable] [unreadable] unknown effects of potential ascertainment bias at a mood disorders clinic versus a community setting, changes in[unreadable] [unreadable] demographics or other sample characteristics that might interact with test performance, and the fact that test[unreadable] [unreadable] performance might degrade when exported from a research framework into a community context, much as[unreadable] [unreadable] therapeutic efficacy estimates usually exceed effectiveness findings. The purpose of the proposed project is to[unreadable] [unreadable] determine the prevalence of BPD in an ethnically diverse community sample and to develop effective means of[unreadable] [unreadable] screening patients in a CMHC for bipolar spectrum disorders, as well as to improve understanding of the early[unreadable] [unreadable] presentation of bipolar spectrum disorders, especially in underserved populations.[unreadable] [unreadable]